Coproduction of styrene and benzaldehyde over a boron nitride-supported monomeric MoOx catalyst

Styrene and benzaldehyde are manufactured by energy-intensive direct dehydrogenation and an intermittent liquid chlorine oxidation batch process, respectively. The coproduction of styrene and benzaldehyde through selective oxidation of ethylbenzene is an environmentally friendly and economically feasible alternative. However, it is hard to control the selectivity for styrene or benzaldehyde as a result of deep oxidation reactions. Here, we report an efficient selective oxidation catalyst, boron nitride-supported monomeric MoO x (MoO x /BN), over which styrene and benzaldehyde can be selectively coproduced. Structure characterization and catalytic evaluation reveal that the MoO x /BN catalyst is conducive to the generation of benzaldehyde and less formation of CO x than for monomeric MoO x supported on inert silica. Based on the kinetic analysis, over MoO x /BN catalyst, styrene is the primary product and benzaldehyde is the major by-product in the subsequent oxidation reaction. The boron hydroxy groups of the MoO x /BN catalyst are involved in the reaction network, which could regulate the reaction behavior of monomeric MoO x species; thus the reaction generates more benzaldehyde.